Somatosensory profiles in acute herpes zoster and predictors of postherpetic neuralgia.

This prospective cohort study aimed to characterize the sensory profile during acute herpes zoster (AHZ) and to explore sensory signs as well as physical and psychosocial health as predictors for postherpetic neuralgia (PHN). Results of quantitative sensory testing of 74 patients with AHZ at the affected site and at the distant contralateral control site were compared to a healthy control group. Pain characteristics (Neuropathic Pain and Symptom Inventory and SES), physical functioning, and psychosocial health aspects (Pain Disability Index, SF-36, and STAI) were assessed by questionnaires. Patients with PHN (n = 13) at 6-month follow-up were compared to those without PHN (n = 45). Sensory signs at the affected site were thermal and vibratory hypesthesia, dynamic mechanical allodynia (DMA), pressure hyperalgesia, and high wind-up (18%-29%), as well as paradoxical heat sensations and pinprick hypalgesia (13.5%). The unaffected control site exhibited thermal and vibratory hypesthesia, DMA, and pressure hyperalgesia. Dynamic mechanical allodynia and pinprick hypalgesia were mutually exclusive. Postherpetic neuralgia was associated with DMA (38.5% vs 6.7%; P = 0.010) and vibratory hypesthesia (38.5% vs 11.1%; P = 0.036) at the control site, with mechanical gain and/or loss combined with normal thermal detection (affected site: 69.2% vs 31.1%; P = 0.023; control site: 53.8% vs 15.5%; P = 0.009). Pain Disability Index (P = 0.036) and SES affective pain perception scores (P = 0.031) were over 50% higher, and 6 of 8 SF-36 subscores were over 50% lower (P < 0.045) in PHN. Sensory profiles in AHZ indicate deafferentation and central but not peripheral sensitization. Sensory signs at distant body sites, strong affective pain perception, as well as reduced quality of life and physical functioning in the acute phase may reflect risk factors for the transition to PHN.

Effects of acupuncture on sensory perception: a systematic review and meta-analysis.

BACKGROUND: The effect of acupuncture on sensory perception has never been systematically reviewed; although, studies on acupuncture mechanisms are frequently based on the idea that changes in sensory thresholds reflect its effect on the nervous system. METHODS: Pubmed, EMBASE and Scopus were screened for studies investigating the effect of acupuncture on thermal or mechanical detection or pain thresholds in humans published in English or German. A meta-analysis of high quality studies was performed. RESULTS: Out of 3007 identified articles 85 were included. Sixty five studies showed that acupuncture affects at least one sensory threshold. Most studies assessed the pressure pain threshold of which 80% reported an increase after acupuncture. Significant short- and long-term effects on the pressure pain threshold in pain patients were revealed by two meta-analyses including four and two high quality studies, respectively. In over 60% of studies, acupuncture reduced sensitivity to noxious thermal stimuli, but measuring methods might influence results. Few but consistent data indicate that acupuncture reduces pin-prick like pain but not mechanical detection. Results on thermal detection are heterogeneous. Sensory threshold changes were equally frequent reported after manual acupuncture as after electroacupuncture. Among 48 sham-controlled studies, 25 showed stronger effects on sensory thresholds through verum than through sham acupuncture, but in 9 studies significant threshold changes were also observed after sham acupuncture. Overall, there is a lack of high quality acupuncture studies applying comprehensive assessments of sensory perception. CONCLUSIONS: Our findings indicate that acupuncture affects sensory perception. Results are most compelling for the pressure pain threshold, especially in pain conditions associated with tenderness. Sham acupuncture can also cause such effects. Future studies should incorporate comprehensive, standardized assessments of sensory profiles in order to fully characterize its effect on sensory perception and to explore the predictive value of sensory profiles for the effectiveness of acupuncture.

Hypnotic relaxation results in elevated thresholds of sensory detection but not of pain detection.

BACKGROUND: Many studies show an effectiveness of hypnotic analgesia. It has been discussed whether the analgesic effect is mainly caused by the relaxation that is concomitant to hypnosis. This study was designed to evaluate the effects of hypnotic relaxation suggestion on different somatosensory detection and pain thresholds. METHODS: Quantitative sensory testing (QST) measurements were performed before and during hypnosis in twenty-three healthy subjects on the dorsum of the right hand. Paired t-test was used to compare threshold changes. The influence of hypnotic susceptibility was evaluated by calculating correlation coefficients for threshold changes and hypnotic susceptibility (Harvard group scale). RESULTS: During hypnosis significantly changed somatosensory thresholds (reduced function) were observed for the following sensory detection thresholds: Cold Detection Threshold (CDT), Warm Detection Threshold (WDT), Thermal Sensory Limen (TSL) and Mechanical Detection Threshold (MDT). The only unchanged sensory detection threshold was Vibration Detection Threshold (VDT). No significant changes were observed for the determined pain detection thresholds (Cold Pain Thresholds, Heat Pain Thresholds, Mechanical Pain Sensitivity, Dynamic Mechanical Allodynia, Wind-up Ratio and Pressure Pain Threshold). No correlation of hypnotic susceptibility and threshold changes were detected. CONCLUSION: Hypnotic relaxation without a specific analgesic suggestion results in thermal and mechanical detection, but not pain threshold changes. We thus conclude that a relaxation suggestion has no genuine effect on sensory pain thresholds. TRIAL REGISTRATION: ClinicalTrials.gov, Identifier: NCT02261155 (9th October 2014).

Acupuncture for post anaesthetic recovery and postoperative pain: study protocol for a randomised controlled trial.

BACKGROUND: We report on the design and implementation of a study protocol entitled Acupuncture randomised trial for post anaesthetic recovery and postoperative pain - a pilot study (ACUARP) designed to investigate the effectiveness of acupuncture therapy performed in the perioperative period on post anaesthetic recovery and postoperative pain. METHODS/DESIGN: The study is designed as a randomised controlled pilot trial with three arms and partial double blinding. We will compare (a) press needle acupuncture, (b) no treatment and (c) press plaster acupressure in a standardised anaesthetic setting. Seventy-five patients scheduled for laparoscopic surgery to the uterus or ovaries will be allocated randomly to one of the three trial arms. The total observation period will begin one day before surgery and end on the second postoperative day. Twelve press needles and press plasters are to be administered preoperatively at seven acupuncture points. The primary outcome measure will be time from extubation to 'ready for discharge' from the post anaesthesia care unit (in minutes). The 'ready for discharge' end point will be assessed using three different scores: the Aldrete score, the Post Anaesthetic Discharge Scoring System and an In-House score. Secondary outcome measures will comprise pre-, intra- and postoperative variables (which are anxiety, pain, nausea and vomiting, concomitant medication). DISCUSSION: The results of this study will provide information on whether acupuncture may improve patient post anaesthetic recovery. Comparing acupuncture with acupressure will provide insight into potential therapeutic differences between invasive and non-invasive acupuncture techniques. TRIAL REGISTRATION: NCT01816386 (First received: 28 October 2012).

Acupuncture point localization varies among acupuncturists.

BACKGROUND: Studies assessing the point-specific effect of acupuncture or the characteristics of acupuncture points (APs) tend to yield inconclusive results. In order to identify a possible confounding factor, we aimed to examine the variability in AP localization by means of a survey. MATERIAL AND METHODS: Attendees of the 14th ICMART (International Council of Medical Acupuncture and Related Techniques) congress as well as DÄGfA (German Medical Society of Acupuncture) lecturers and students were asked to locate and mark the APs LI 10 and TH 5 on a research assistant's arm. Identified points were transferred into a coordinate system, and the respective bivariate distribution function was calculated. Additionally, participants filled out a questionnaire about their acupuncture education and experience, the acupuncture style and point localization techniques used most frequently, and their estimation of the size of an AP. RESULTS: The areas of the ellipses, theoretically containing 95% of AP localizations, varied between 44.49 and 5.18 cm(2). The largest distance between 2 identified points was 8.45 cm for LI 10 and 5.3 cm for TH 5. Apart from being trained at the same school, no other factor could be identified that determined the variability in AP localization. CONCLUSION: Our results indicate that congruity of AP localization among experienced acupuncturists might be low. Although there are some limitations to our results, this possible bias should be taken into account when conducting acupuncture trials and interpreting results of previous acupuncture studies.

Deqi sensations without cutaneous sensory input: results of an RCT.

BACKGROUND: Deqi is defined in relation to acupuncture needling as a sensory perception of varying character. In a recently published sham laser validation study, we found that subjects in the verum and the sham laser group experienced deqi sensations. Therefore, we aim to further analyze whether the perceptions reported in the two study arms were distinguishable and whether expectancy effects exhibited considerable impact on our results. METHODS: A detailed re-analysis focusing on deqi sensations was performed from data collected in a previously published placebo-controlled, double-blind, clinical cross-over trial for a sham laser evaluation. Thirty-four healthy volunteers (28 ± 10.7 years; 16 women, 18 men) received two laser acupuncture treatments at three acupuncture points LI4 (hégu), LU7 (liéque), and LR3 (táichong); once by verum laser and once using a sham device containing an inactive laser in randomized order. Outcome measures were frequency, intensity (evaluated by visual analogue scale; VAS), and quality of the subjects' sensations perceived during treatments (assessed with the "acupuncture sensation scale"). RESULTS: Both, verum and the sham laser acupuncture result in similar deqi sensations with regard to frequency (p-value = 0.67), intensity (p-value = 0.71) and quality (p-values between 0.15 - 0.98). In both groups the most frequently used adjectives to describe these perceptions were "spreading", "radiating", "tingling", "tugging", "pulsing", "warm", "dull", and "electric". Sensations reported were consistent with the perception of deqi as previously defined in literature. Subjects' conviction regarding the effectiveness of laser acupuncture or the history of having received acupuncture treatments before did not correlate with the frequency or intensity of sensations reported. CONCLUSIONS: Since deqi sensations, described as sensory perceptions, were elicited without any cutaneous sensory input, we assume that they are a product of non-specific effects from the overall treatment procedure. Expectancy-effects due to previous acupuncture experience and belief in laser acupuncture do not seem to play a major role in elicitation of deqi sensations. Our results give hints that deqi might be a central phenomenon of awareness and consciousness, and that its relevance should be taken into account, even in clinical trials. However, further research is required to understand mechanisms underlying deqi.